Semiconductor Chip Manufacturing is a complicated multistep process. At each step, a semiconductor wafer may be subjected to some type of chemical process that changes the wafer's structure. Residue or debris may be left on the wafer from a particular chemical process. That residue must be cleaned from the wafer without damaging the partially completed chip structures. One way these wafers are cleaned is washing, i.e., applying a fluid onto the wafer and then, wiping the fluid off with a cleaning pad.
Typical prior art rollers used for cleaning semiconductor wafers included some type of metallic material. However, metals corrode; Corrosion diminishes the pad's cleaning effectiveness. Also, the metal from the roller dissolves, slightly, introducing metallic ions into the cleaning process. These metallic ions may contaminate the wafer rather than cleaning it.
Also, other types of foreign material from the pad may contaminate the wafer or circuit, defeating the purpose of cleaning. One source of contamination was the means of attaching the pad to the cleaning apparatus. Some prior art cleaning pads are permanently attached to a roll for easy assembly/disassembly. Typically, they are attached to the roll with glue or metal staples. However, glue may melt, mixing with and contaminating the cleaning solutions. Staples may corrode, providing another source of corrosion. Additionally, staples may project above the pad surface, to scratch the wafer surface being cleaned. Thus, there is a need for an improved cleaning pad and roll assembly.